Disk bit



` `xme 12, 1928. V HL H. HOLDWAY ET AL,

K DISK BIT Filed April 14, 1924 Patented June 12, 1928.

UNITED STATES PATENT OFFICE.

liIALL H. HOLDAWAY, F LOS ANGELES, AND THOMAS D. CAMPBELL, OF PASADENA,

- CALIFORNIA. y

msx Brr. i

Application filed April 14, 1924. Serial No. 766,280.

Heretofore, the disk bits employed in' drilling of deep wells such as oil wells ,have l0 had altendency to force the material out by the disk up against the body of the bit holding the disk, with the result that such n iater' ial, which is'mixed with flushing fluid during the drilling process would become packe l against the body of the bit during the drill ing operations and interfere with the effective drilling of the well; or such disk bitsV as have hitherto' been designed to force the dbris cut and mud developed in the well away from the disks and body of the bit have not been correctly designed and constructed to effect the proper shearing action upon the formation and have further operated to cut around the center of the well hole, leaving a core of uncut material inthe bottom of the hole which seriously interfered with the effectiveness of the bit, except in very soft formations.

An object of the present invention is to provide a bit employing disk vcutters by which the debris and mud formed during drilling operations will be forced away from the space between the disks and prevented from pasing up against the bottom of the body of the bit. and by which a well hole may be formed in which aminimum core will'be produced, so that the bit may be employed for drilling other than in the very softest formations and will in no formation tend to clog on account of the mud or dbris formed in the well hole.

Another objectl of the present invention is to provide such a disk cutter and method of Ymounting and securing the disk cutter to the body of the bit, that the cutter or disk will operate upon the formation by a combined shearing and slicing action. y

Various other'objects and advantages of I l The bosses 6 are provided with outwardly the present invention will be understood from ings, wherein there is illustrated the invention in its-preferred embodiment.

In the accompanying drawings:

Fig.- 1 is an elevation of one embodiment of the invention.

Fig. 2 is an enlarged elevation of the lower end of the bit, the same being partially in vertical section.

Fig. 3 is a bottom view.

Referring to the drawings, the rotary drilling bit is shown as comprising a body 1 which is provided with an enlargement 2 near its upper end and terminates at the upper end in a screw-threaded pin 3 by which the bit may be attached to a drill rod and rotated in a drilling operation, the threaded stem 3 of the bit preferably being tapered upwardly as indicated. The shank of the body 1 should be preferably long in comparison with its diameter, and terminates at itselower end in a Wedge-shaped extension 4 which thus provides two opposed downwardly and inwardly inclined faces 5. From each inclined face 5 a boss extends outwardly, the bosses 6 being odset from the center of the faces 5 in opposite directions, so that, as later described, the cutters mounted thereon are positioned one in advance of the other.

30 tapered sides 7 and with a recess 8 in their end-face. 9 indicates collars for mounting rotating cutter or disksl() upon the body 1. each collar 9 being enlarged at its outer end 11 to provide 'a means for holding a disk 10 upon the body 1. Each collar 9 also provides a shell extension 11a which fits over the `side 7 of the bos/s 6. The collars 9 are also provided with an extension 12 fitting in the recess8 at the end of the bpss so that the collar 9 is prevented from being sheared off the boss 6 both by the shell 11a extending over the outer face of the boss and by contact between the extension 12 and such boss. The collar 9 is held to thel body by means of a pin 13screwed through .the center of the collar 9 and boss 6. f

Due to the angle of the wedged extension' 4 of the body, the disk cutters 10 are thus positioned in inclined planes which converge 10G below the body of lthe bit .and thereby the lower edges of the disk cutters are brought close together, with the result that little space exists between the opposed disks where a hard core may be left when the drill is employed.

The disks 10 are provided with a plurality of step cutting edges each making a slight angle with the plane of rotation of the disks. outer cutting faces 1-5 bent outwardly from the hub of the-disk so that such faces 15 of the disk joining the cutting edges 15 are relieved inwardly from the cutting edges. Such faces are found to increase the shearing action of the cutters.

Again referring to the body 1 of the bit, the body 1 is enlarged slightly above the disks 10, as indicatedat 16, to house flushing ducts 17 which extend through the body of the bit vin order to conduct flushing fluid to the disk from the top of the well. Such ducts 17 discharge agalnstthe edges of the cutters 10, and preferably to that side of the axis of the disks which will enable the flushing iuid to operate to rotate the disks. It will be noted that, as the disk cutters 10 are relieved inwardly from the outer .face of the disks, the same are intended to be pushed around by the body 1 of the disk or rotated counter-clockwise as viewed in Fig. 3.l In such case the disk cutters 10 will f tend to rotate relative to the body 1 counterclockwise as viewed in Fig. 1, so that Aby 'discharging the water from ythe ducts 17 from near the center of the body 1, such water operates to aid in rotating the disks.

. The drilling bit herein described will inA operation rapidly remove material from the bottom of the well hole, vand the material removed will be vforced by the disk outwardly away fromv fthe bodyof the bit so that such material passes' upwardly past the body without tending to become packed and clog operation of the bit. The lower of the disk, will in operation operate to slice into the material as well as by a straight shearing action'upon the same, which is found to result in a substantial increase in the rate of drilling of such a bit.

While the rotary drilling bits herein described are well suited for the purposes of this invention, various modifications may The disks 10 also have theirbeA made in the form of the bits herein described without. departing .from the spirit of the invention. 'I'he invention is not limited. to the' detatils of construction of such examples ofthe invention, but is of the full sco e set forth in the appended claims.

1. A rotary drilling bit comprising, a body, disk cutters mounted on the body so as to lie in inclined planes converging below the body, said cutters having their periphe'y brought to a thin cltting edge. of insu cient thickness for crushing the formation, the peripheral cutting edge of said cutters 'having step-like portions angled slightly Aso as to lie in planes converging below the body, the disk cutters being arran ed with their cutting. faces facing outw r ly from the body, the disk cutters having their .periphery brought to a cutting edge of insuiiicient thickness for. crushing the formation, thecutting edge of the cutter being further .formed in a plurality of shearing faces angled 'but slightly relatlve to the plane of 3. A vrotary drilling bit comprising, a body having a single lower extension, a disk cutter mounted upon each side of such extension, the cutters being positioned one in advance of the other and Aprovided with cuttin extension, the cutters being brought to thin cuttin faces of insufiicient thickness for operating upon the formation by a crushfaces facing outwardly from theing action, the cutting faces being formed in a plurality yof step cutting'portions, the

edges ofA which are disposed at a slight angle to the plane of the disk.

4. A rotary drilling bit comprising, a bodyhaving twofdisk -cutters mounted thereon, said disk cutters. being mounted one in vadvanceof the other and in converging planes, the disk cutters being brought to relatively narrow non-crushing cuttln i. edges, said cutting 'edges facing away 'om the body and being in step-like portions angled slightly relative to the plane of the disk, there being interconnecting portions of the cutting edge whereby the cutting edge of the disk is made continuous. .Y Y

Signed .at Los Angeles, California, this 20th day of March, 1924.`

- HALL H. HOLDAWAY.

' THOMAS D. CAMPBELL. 

